Polysilane derivatives of the transition metals II. The crystal and molecular structure of [tris(trimethylsilyl)silyl]pentacarbonylmanganese, (Me3Si)3SiMn(CO)5

The crystal and molecular structures of tris(trimethylsilyl)silyl]pentacarbonylmanganese, (Me₃Si)₃SiMn(CO)₅, have been determined from three-dimensional X-ray data obtained by counter methods. The compound crystallizes in space group P$\text{1}$ of the triclinic system, with two molecules in a unit cell of dimensions: a = 9.002(2), b = 9.655(2), c = 15.639(3) Å, α = 83.66(1), β = 105.65(1), γ = 114.61(1)°.The observed and calculated densities are 1.20 (±0.03) and 1.23 g-cm^?3 respectively. Full-matrix least-squares refinement of the structure has led to a final value of the conventional R factor of 0.059 for the 818 independent reflections having F² > 3σ(F²).The coordination geometry about the manganese atom is approximately octahedral and, about the silicon atom bonded to the manganese atom, tetrahedral.The relative orientations of carbonyl and trimethylsilyl groups, when viewed down the MnSi bond, appear consistent with minimization of energy due to nonbonded interactions.Two of the equatorial carbonyl groups are displaced out of the equatorial plane towards the silicon ligand by 6°. The SiMn bond is 2.564(6) Å long and has no multiple character.